What is going on here is the same set of problems that effected the stream groups, i.e.
The for profit freight RxRs don't want a train on their RxR if there is any chance that it will break down or otherwise cost them money.
The result may be that it can only run on it's home RxR or just be a static display. While sad, business is business.
Take the Steamtown example ... they have trouble with the RxR they run on every time they have a problem (train de-railed a year or two ago because of poor quality rail). The current mngt now states their mission isn't to run railfan trips, so they are running less trips
Meanwhile the trolley group there has been expanding & expanding (they also run on soomeone else's RxR tracks).
Here on LI the engine 39 group thinks they'll be able to run on LIRR tracks once they get her running again. Once they ask the mngt for permission I'll be they reply with an impossible list of demands & restrictions